Treating complex ores or their concentrates.



WILLIAM MORLEY MARTIN, OF REDRUTH. ENGLAND.

TREATING COMPLEX ORES OR THEIR GONCENTRATES.

N0 Drawing.

Specification of Letters Patent.

PatentedJulyS, 1913.

Application filed April 15, 1910. Serial No. 555,632.

To all QUZLOWZ it may concern Be it known that; I, lViLmxM, Moininf lvttn'ri'x, a subject of the King oi (i reat Britain, residing at 5 'lrewirgie road, Red ruth, in the county oi Cornwall. l lngland. analytical chemist, have invented certain new and nsei'ul Improvements in 'lreating Complex Ores or Their Concentrates, oi? which the following is a. s nzcitication.

In my application for United States Lett ers Patent. No. 345,520 dated 23rd l ebri'n ary 1910, I have described a process oil? treating complex ores consisting in rendering them more amenable to concentration and to the separation of their constituent minerals by that. form of water concentration which depends on se 'iaration by water owing to differences in size and speeilie grav ity of the jiarticles, which process of treating consists in mixing the subdivided ore or a com-tntrat'e thereof with a solution oi. an oxidizing agent adapted partially to oxid'ze the ore at a raised temperature, 1 ating the mass and subjecting tho mass to any process of water concentration as above detined. It. was explained in that specilication that by the term conceniration proeesses I do not include leaching or processes which operate thereby. ll; was also explained that the action of the oxidizing agent is not known to me, since although oxidation may occur it is uncertain whether this oxidation is the cause oi the result or whether it is a mere accident to the actual cause.

l\l y present invention relates to a treatment of complex ores or concentrates thereot by mixing such ore or concentrate in a sub-divided state with a solution oi a suit able oxidizing agent and exposing the mass to a temperature between ordinary temperature and a temperature of about 2100 C.

The best oxidizing agents tor mixing with the subdivided ore are nitrates whether used in solution, though the more active agents like a biohromate or a permanganate have in many cases a better effect: at ordinary temperatures than a nitrate has.

The proportion of the oxidizing agent to be used varies with the nature of the ore or concentrate to be treated. but generally speaking the smaller the proportion of gangue in an ore the larger must be the proportion of the oxidizing agent. so a coneentrate requires a more liberal quantity of the agent than the oracle ore. On the other hand when one oi the valuable eon stituents oi the ore is in a very line state of division. the quantity oi the agent may be smaller than when all the constituents are less linrly divided. in any case the proportion, is comparatively small. about two per cent. oi the weight oi the ore generally suilicing tor a crude ore.

l have tound that in the case oi. many ores. especially those containing sullids of lead and zinc together with ll'( n pyriles. ii the mass which has been heated with the oxidizing agent, or the mass which has been saturated with the solution ot the oxii lizing agent and subsequently heated or not. is subjected to a limited oxidizing roasting operation. the iron pyrites. in so in as it may not have been already oxidized, may he oxidized first; the. mass may then be subjected to water concentration to separate the oxid oi iron trom the sultiles oi laid and zinc and the said suliids may again be subjected to a limited oxidizing rrasting in order to oxidize the zinc sullid. second concentraticn will now separate the zinc oxid and suliate (it any) irem the lead sullid.

in some cases the limited roasting may be. carried iar enough to oxidize both the pyrites and the zinc sull'id, a single concentration then serving to separate the lead suliid. separation ol the iron and zinc. oxids being otherwise eil'eeted. The possibility oi ctlecting such a tlili'erential calcination or roasting arises i'rom the preliminary treatment with an oxidizing agent. in one oi the ways above described.

As examples oi the process the iollowing may be. given 1. A, complex sullid ore containing lead and zinc is suitably subdivided and saturated with a solution oi? sodium nitrate: when necessary for complete saturation the ore may be stirred with the solution in any appropriate manner. The strength oi? the solution should be such as to introduce the required proportion of the oxidizing agent into the mass ol. ore, per cent. of the weight oi" the ore being appropriate in many cases. The excess of liquid, iii any, is now drained away and the ore concentrated by a water concentration process as above defined, either without lirst drying it, or after it has been dried with or without gentle heating, such as to a temperature oi. l20 l.

A complex suliid ore containing lead and zinc together with iron pyrites is suittill ably subdivided and treated with sodium nitrate in the manner described in Example 1. The mass is then subjected to a limited roasting operation by heating it in a furnace of the kind usually used for roasting, to which furnace the supply of air is limited. The iron pyrites will be oxidized rapidly and the process is easily stopped at this stage. The cooled roasted ore is then concentrated by a water concentration process as above defined to separate the oxidized pyrites from the other metalliferous minerals, whereupon the treatment with sodium nitrate is repeated and the mass is again subjected to a limited roasting operation to oxidize the lead sulfate, and finally concentrated.

Having thus described my said invention and the best means I know of carrying the same into practical effect, I claim 1. A process of treating complex ores containing sulfids of lead and zinc, or concentrates thereof, so as to recover the valuable constituents in a separated condition, which process consists in mixing the sub-divided ore with a solution of an oxidizing agent in proportion insuflicient to desulfurize the ore, then exposing the mass to a temperature not exceeding 300 0., then gravitally separating the mixture by water.

:2. A process of treating complex ores containing sulfids of lead and zinc, or concentrates thereof, so as to recover the valuable constituents in a separated condition, which process consists in mixing the sub-divided ore with a solution of an oxidizing agent in proportion insul'iicient to desulfurize the ore, then exposing the mass to a temperature not exceeding 300 C., then subjecting the mass to a differential roasting, and gravitally separating by water to separate a constituent.

3. A process of treating complex ores containing sulfids of lead and zinc, or concentrates thereof, so as to recover the valuable constituents in a separated condition, which process consists in mixing the subdivided ore with a solution of an oxidizing agent in proportion insuflicient to desulfurize the ore, then drying the ore after treatment with the solution, then subjecting it to a diiferential roasting, and gravitally separating by water to separate a constituent.

4. A process of treating complex ores containing sulfids of lead and zinc, or concentrates thereof, so as to recover the valuable constituents in a separated condition, which process consists in mixing the subdivided ore with a solution of an oxidizing agent in proportion insufiicient to desulfurize the ore, then subjecting the mass comprisingthe ore and the said agent to a differential roasting, gravitally separating by water to separate a constituent, and then successively repeating the operations of roasting and concentrating to separate other constituents.

5. A process of treating complex ores containing sulfids of lead and zinc, or concentrates thereof, so as to recover the valuable constituents in a separated condition, which process consists in mixing the subdivided ore with a solution of an oxidizing agent in proportion insufficient to desulfurize the ore, then heating the mass comprising the ore and the said agent, then subjecting the mass to a differential roasting, gravitally separating by water to separate a constituent, and then successively repeating the operations of roasting and concentrating to separate other constituents.

6. A process of treating complex ores containing sulfids of lead and zinc, or concentrates thereof, so as to recover the valuable constituents in a separated condition, which process consists in mixing the subdivided ore with a solution of an oxidizing agent in proportion insuflicient to desulfurize the ore, then drying the ore after treatment with the solution, then subjecting it to a differential roasting, gravitally separating by water to separate a constituent, and then successively repeating the operations of calcining and concentrating to separate other constituents.

In testimony whereof I have signed my Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). C. 

